What is Technical SEO?
The crawling, indexing, rendering, and performance work that lets search engines reach, understand, and serve your pages. It covers directives, architecture, speed, and structured data rather than words on the page.
Related terms
Crawling
How search-engine bots discover pages by following links, sitemaps, and directives. If a URL is never crawled, it cannot be indexed no matter how good its content is.
Indexing
Storing and organizing crawled pages so they can be retrieved for queries. Indexing is selective: crawled does not mean indexed, and indexed does not mean ranking.
Core Web Vitals
Google’s field-measured experience metrics: Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift. Roughly half of origins pass all three, so the work remains relevant.
Crawl Budget
The number of pages a search engine will crawl on a site in a given period, driven by server capacity and demand signals. Large or slow sites must spend it on indexable, valuable URLs.
Robots.txt
A plain-text file at the domain root telling compliant crawlers which paths they may fetch. It controls crawling, not indexing: blocked URLs can still be indexed by URL if linked.
XML Sitemap
A machine-readable list of canonical URLs worth crawling, optionally with last-modified dates. One file holds 50,000 URLs or 50 MB uncompressed; larger sites segment by template or locale.